diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 0ee12881..6d3db105 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1 +1 @@
-{".":"9.0.0"}
+{".":"9.1.0"}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9c907835..1c90f9b0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## [9.1.0](https://github.com/ClosureTree/closure_tree/compare/closure_tree/v9.0.0...closure_tree/v9.1.0) (2025-07-23)
+
+
+### Features
+
+* migrate from ActiveSupport::Autoload to Zeitwerk ([#457](https://github.com/ClosureTree/closure_tree/issues/457)) ([d18e80c](https://github.com/ClosureTree/closure_tree/commit/d18e80cdbd4f3510377363bc7b5166f0cc1b0a6f))
+
 ## [9.0.0](https://github.com/ClosureTree/closure_tree/compare/closure_tree-v8.0.0...closure_tree/v9.0.0) (2025-07-21)
 
 
diff --git a/lib/closure_tree/version.rb b/lib/closure_tree/version.rb
index 8cfede6f..97bbcc7a 100644
--- a/lib/closure_tree/version.rb
+++ b/lib/closure_tree/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module ClosureTree
-  VERSION = Gem::Version.new('9.0.0')
+  VERSION = Gem::Version.new('9.1.0')
 end